Research report: New spatial records of vascular plants in the Azores Archipelago: the PRIBES project and the Azorean Biodiversity Portal (ABP) initiatives – II. Pico Island

The dataset improves the spatial knowledge of plant distributions on Pico but does not measure changes in plant abundance, diversity or ecosystem condition. The project forms part of the PRIBES initiative and a collaboration with the PORBIOTA project, which is intended to map Azorean biodiversity for the AZORES BIOPORTAL. It is the second paper in the PRIBES series, following publication of new spatial plant records for São Jorge Island.

The Azorean Biodiversity Portal is a regional database that compiles georeferenced records of marine and terrestrial taxa from historical literature, collections and field observations. Field activities included site selection and fieldwork by Fernando Pereira and Rui B. Elias, following authorisation from the Azorean Regional Directorate for the Environment.

Rui B. Elias also conducted fieldwork and site selection. Andrea Petrone and Rui B.

Elias served as taxonomists, while Andrea Petrone and Paulo A. V. Borges were responsible for the Darwin Core databases.

These activities link field observations and taxonomic identification with standardised geospatial records for the regional database. The inventory was conducted on Pico, the second-largest of the nine volcanic islands in the Azores Archipelago. The archipelago lies in the North Atlantic at approximately 37–40° N and 25–31° W, about 1,600 km west of mainland Portugal.

Pico covers approximately 447 km², measures about 42 km from east to west and 15 km from north to south, and reaches 2,351 m above sea level at Mount Pico, the highest point in Portugal. Described as the youngest island in the archipelago, Pico has an age of approximately 0.27 million years. Pico’s volcanic and tectonic setting creates pronounced environmental gradients.

Its three principal volcanic units are the older Topo volcano, an intermediate volcanostratigraphic unit containing basaltic spatter cones, and the younger Madalena Volcanic Complex, which includes fissural systems and the Pico stratovolcano with its summit pit crater. Historical eruptions in 1562–64, 1718 and 1720 produced recent lava fields locally known as the “Misterios.” Young, poorly developed andisols predominate, while organic soils and peat occur in depressions and at higher elevations. Climate also varies markedly with altitude.

Mean annual temperature at sea level is approximately 17.4–17.5°C, with limited seasonal variation. Precipitation occurs throughout the year and increases from about 1,000–1,900 mm at low elevations to more than 4,000 mm above 700 m. Fog and cloud interception are important between roughly 180 and 700 m, average relative humidity is around 80%, and snowfall may occur above 2,000 m.

These climatic and topographic gradients shape the island’s sequence of coastal woodlands, lowland and montane forests, submontane forests, and alpine scrublands. Although human colonisation has substantially transformed Pico through forest clearance for agriculture and pasture, wood extraction and the introduction of alien species, the island retains some of the Azores’ best-preserved natural habitats. Its limited agricultural potential and low level of urbanisation have helped sustain large areas of natural and semi-natural vegetation.

The island preserves nearly the complete sequence of vegetation belts, from Erica–Morella coastal woodlands at 0–100 m to Calluna alpine scrublands above 1,700 m, creating substantial ecological heterogeneity. The principal reported contribution is improved spatial documentation of plant distributions on Pico. The occurrence dataset provides a more explicit record of where vascular plants have been observed and can support island biogeography, long-term ecological monitoring, conservation strategies and further studies of Azorean biodiversity.

This is a field-based inventory and dataset study rather than a comparative experiment, and it is geographically bounded to Pico Island, with an emphasis on exotic potentially invasive vascular plants in natural and semi-natural areas. The available project description does not report sampling effort or detection uncertainty, and the inventory does not establish trends in species richness, invasive-plant impacts or ecosystem condition.

Subject of Research: Georeferenced field inventory of vascular plants in natural and semi-natural areas of Pico Island, Azores

Article Title: New spatial records of vascular plants in the Azores Archipelago: the PRIBES project and the Azorean Biodiversity Portal (ABP) initiatives – II. Pico Island

Article References: Petrone, A., Borges, P., Pereira, F., & Elias, R. (2026). New spatial records of vascular plants in the Azores Archipelago: the PRIBES project and the Azorean Biodiversity Portal (ABP) initiatives – II. Pico Island. Biodiversity Data Journal, 14, Article e206276. https://doi.org/10.3897/bdj.14.e206276

Image Credits: AI Generated

DOI: 10.3897/BDJ.14.e206276

Keywords: Pico Island, Azores, vascular plants, biodiversity inventory, georeferenced records, PRIBES, Azorean Biodiversity Portal, plant distributions, spatial, records, vascular, plants